Here's a fun little exercise. How would MLB look if players were on the roster of the team which originally signed them? Marquis goes back to the Braves, Holliday returns to the Rockies, etc.
Sounds like the ranking is informal, and the series isn't quite finished (Friday they got to #5, the Yankees). The Rockies come in at 7th with a bare bullpen but impressive depth in the lineup. (Some of you will be happy that Clint Barmes didn't even make the team. Most of you will be infuriated the guy picked Spilborghs and Pierre over Smith in the OF.)
It's a fun but casual way of looking at how teams have performed with amateur signings and development of that talent (for the most part, since some of these players left the organization early). Obviously, it leaves out a lot of what the player development arm of an organization does (trades, rule 5 drafts, and minor league free agent signings aren't counted).